Having suffered from serious pollutions, he made up his mind to devote his life to __________ pollution from __________ again.
| A．preventing; happening |
| B．prevent; happen |
| C．preventing; happens |
| D．preventing; will happen |
The girl behaved in a strange way. You couldn’t her mind.
| A．read | B．realize | C．recognize | D．see |
I feel it is you as well as your wife that for your son’s bad performance at school.
| A．are to blame | B．is to be blamed | C．are to be blamed | D．is to be blamed |
Where on earth have you been? We you back much earlier.
| A．were expecting | B．are expecting | C．had expected | D．expect |
He works in a factory now, but he on a farm for 20 years.
| A．worked | B．has worked | C．had worked | D．had been working |
Glad to see you back. How long in Russia?
| A．did you stay | B．have you stayed | C．were you staying | D．have you been staying |